U.S. patent application number 14/915501 was filed with the patent office on 2016-07-28 for fluid composition comprising crosslinked polyvinylpyrrolidone for oil field applications.
This patent application is currently assigned to ISP INVESTMENTS INC.. The applicant listed for this patent is ISP INVESTMENTS INC.. Invention is credited to Cuiyue LEI, Mohand MELBOUCI, Osama M. MUSA, Janice Jianzhao WANG.
Application Number | 20160215196 14/915501 |
Document ID | / |
Family ID | 52628837 |
Filed Date | 2016-07-28 |
United States Patent
Application |
20160215196 |
Kind Code |
A1 |
WANG; Janice Jianzhao ; et
al. |
July 28, 2016 |
FLUID COMPOSITION COMPRISING CROSSLINKED POLYVINYLPYRROLIDONE FOR
OIL FIELD APPLICATIONS
Abstract
Disclosed herein is a water based High-Temperature High-Pressure
(HTHP) fluid composition having a density of about 8.3 to about
21.0 ppg, comprising: (i) a brine based fluid; (ii) about 0.5 ppb
to about 20 ppb of crosslinked polyvinylpyrrolidone (PVP); (iii)
about 5 ppb to about 100 ppb of bridging agents selected from the
group consisting of CaCO.sub.3 and sized salts; and (iv) optionally
about 0 ppb to about 25 ppb of Fluids Loss Additives (FLA), wherein
the crosslinked PVP is prepared by precipitation polymerization of
vinylpyrrolidone (VP) in an organic solvent in the presence of a
crosslinking agent and a free radical polymerization initiator,
wherein the crosslinking agent is present in an amount of from
about 0.1 wt. % to about 5.0 wt. % based on the weight of the
vinylpyrrolidone. Also discloses a method of drilling and
completing operations in a subterranean formation.
Inventors: |
WANG; Janice Jianzhao;
(Hockessin, DE) ; MELBOUCI; Mohand; (Wilmington,
DE) ; LEI; Cuiyue; (Wayne, NJ) ; MUSA; Osama
M.; (Kinnelon, NJ) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ISP INVESTMENTS INC. |
Wilmington |
DE |
US |
|
|
Assignee: |
ISP INVESTMENTS INC.
Wilmington
DE
|
Family ID: |
52628837 |
Appl. No.: |
14/915501 |
Filed: |
July 30, 2014 |
PCT Filed: |
July 30, 2014 |
PCT NO: |
PCT/US14/48913 |
371 Date: |
February 29, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61874928 |
Sep 6, 2013 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C09K 8/685 20130101;
C09K 8/24 20130101; C09K 8/512 20130101; C09K 8/588 20130101; E21B
7/00 20130101; C09K 2208/18 20130101; C09K 8/12 20130101; C09K
2208/34 20130101 |
International
Class: |
C09K 8/12 20060101
C09K008/12; E21B 7/00 20060101 E21B007/00; C09K 8/512 20060101
C09K008/512 |
Claims
1. A water based High-Temperature High-Pressure (HTHP) fluid
composition having a density of about 8.3 to about 21.0 ppg,
comprising: i. a brine based fluid; ii. about 0.5 ppb to about 20
ppb of crosslinked polyvinylpyrrolidone (PVP); iii. about 5 ppb to
about 100 ppb of bridging agents selected from the group consisting
of CaCO.sub.3 and sized salts; and iv. optionally about 0 ppb to
about 25 ppb of Fluids Loss Additives (FLA), wherein the
crosslinked PVP is prepared by precipitation polymerization of
vinylpyrrolidone (VP) in an organic solvent in the presence of a
crosslinking agent and a free radical polymerization initiator,
wherein the crosslinking agent is present in an amount of from
about 0.1 wt. % to about 5.0 wt. % based on the weight of the
vinylpyrrolidone.
2. The water based HTHP fluid composition according to claim 1,
wherein the fluid composition is employed as a drill-in fluid
composition, a completion fluid composition or a workover fluid
composition.
3. The water based HTHP fluid composition according to claim 1,
wherein the brine based fluid is selected from the group consisting
of sodium chloride, potassium chloride, calcium chloride, magnesium
chloride, ammonium chloride, zinc chloride, sodium bromide, calcium
bromide, zinc bromide, potassium formate, cesium formate, sodium
formate, and combinations thereof.
4. The water based HTHP fluid composition according to any one of
claim 1 being suitable for high-temperature high-pressure (HTHP)
drill-in, workover or completion operations having a temperature of
250.degree. F. or above.
5. The water based HTHP fluid composition according to claim 1
having a pH of from about 6.0 to about 13.0.
6. The water based HTHP fluid composition according to claim 1,
wherein the crosslinked PVP is in the form of fine white
powder.
7. The water based HTHP fluid composition according to claim 1,
wherein the crosslinked PVP is totally dissolved into solution.
8. The water based HTHP fluid composition according to claim 1,
wherein the precipitation polymerization temperature is varied from
about 40.degree. to about 150.degree. C.
9. The water based HTHP fluid composition according to claim 1,
wherein the organic solvent comprises an aliphatic hydrocarbon
having a C.sub.3-C.sub.10 saturated hydrocarbon, branched or
unbranched, cyclic or acylic, or mixtures thereof.
10. The water based HTHP fluid composition according to claim 1,
wherein the precipitation polymerization is conducted at about
10-50 wt % solids.
11. The water based HTHP fluid composition according to claim 1,
wherein the crosslinking agent comprises at least two olefinic
double bonds.
12. The water based HTHP fluid composition according to claim 11,
wherein the crosslinking agent is selected from the group
consisting of N,N'-divinylimidazolidone (DVI),
N,N',N''-triallyl-triazine-trione, methyene-bis-acryamide,
methylene-bis-(meth)acrylamide, triallyl amine, triallylglucose,
ethyleneglycol-di-(meth)acrylate,
diethyleneglycol-di-(meth)acrylate,
triethyleneglycol-di-(meth)acrylate,
tetraethyleneglycol-di-(meth)acrylate,
polyethyleneglycol-di-(meth)acrylate,
pentaerythritol-tri-allylether, pentaerythritol-di-allylether,
pentaerythritol-tetra-allylether,
pentaerythritol-di-(meth)acrylate,
pentaerythritol-tri(meth)acrylate,
pentaerythritol-tetra-(meth)acrylate,
1-vinyl-3-(E)-ethylidene-pyrrolidone (EVP), allyl methacrylamide,
allyl glycidyl ether, glycidyl acrylate, hydroxyacrylamide,
triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione,
2,4,6-triallyloxy-1,3,5-triazine and divinylbenzene, and
combinations thereof.
13. The water based HTHP fluid composition according to claim 11,
wherein the crosslinking agent is selected from the group
consisting of N,N'-N,N' -divinylimidazolidone (DVI),
pentaerythritol-tri-allylether,
triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione,
2,4,6-triallyloxy-1,3,5-triazine, and combinations thereof.
14. The water based HTHP fluid composition according to claim 1,
wherein the free radical polymerization initiator is selected from
the group consisting of acyl peroxides, diacetyl peroxide,
dibenzoyl peroxide, dilauryl peroxide, peresters, t-butylperoxy
pivalate, tert-butyl peroxy-2-ethylhexanoate, peroxides,
di-tert-butyl peroxide, percarbonates, dicyclohexyl
peroxydicarbonate, azo compounds, 2,2'-azobis(isobutyronitrile),
2,2'-azobis(2,4-dimethylvaleronitrile),
1,1'-azobis(cyanocyclohexane), 2,2'-azobis(methylbutyronitrile),
and combinations thereof.
15. A method for drilling into a producing zone with limited
formation damage in a subterranean formation, comprising the steps
of: a. drilling a borehole into a formation adjacent to the
producing zone; b. circulating the water based HTHP fluid
composition of claim 1 in the borehole; and c. drilling into the
producing zone while continuing step (b).
16. A method for conducting a completion operation in a
subterranean formation, comprising using the water based HTHP fluid
composition of claim 1 in the completion operation.
17. The method according to claim 16, wherein the completion
operation is cementing a borehole.
18. The method according to claim 16, wherein the completion
operation comprises isolating or consolidating a narrow gradient
zone in the formation.
Description
FIELD OF THE INVENTION
[0001] The present application relates to oil-well servicing fluids
compositions, and more particularly, relates to a
High-Temperature-High-Pressure (HTHP) stable fluid compositions and
its applications in water based HTHP drill-in and completion and
workover fluids, a process for preparing the same and a method of
use.
BACKGROUND OF THE INVENTION
[0002] Drilling fluids used in drilling a well in a subterranean
formation comprise gaseous or liquid, and mixtures of fluids and
solids including solid suspensions, mixtures and emulsions of
liquids, gases and solids used to drill well bores into
subterranean formations. Such fluids are primarily employed to cool
the drill bit, lubricate the rotating drill pipe to prevent it from
sticking to the walls of the well bore, and prevent blowouts by
serving as a hydrostatic head to counteract the sudden entrance
into the well bore of high pressure formation fluids, and remove
drill cuttings from the well bore.
[0003] Further, the drilling fluids are utilized when drilling a
wellbore through rock formations in order to sweep the rock
cuttings created at the bit up to the surface where they are
removed. To control downhole pressures, the fluid's density is
usually increased by adding a powdered dense mineral. The fluid can
exhibit sufficient viscosity to provide efficient cuttings removal
(hole-cleaning), and sufficient gel strength for the stable
suspension of the mineral. Drilling fluids can also exhibit a low
filtration rate in order to lessen the possibility of differential
sticking.
[0004] Drill-in fluids are employed for drilling through the
reservoir section of a subterranean formation. Drill-in fluids can
be used, for example, but not by way of limitation (i) to drill the
reservoir zone satisfactorily, which is either a vertical or a
long, horizontal drain hole; (ii) to minimize the damage of the
near-wellbore region and maximize the production of exposed zones,
and (iii) to facilitate the necessary well completion. The drill-in
fluids may resemble completion fluids. Drill-in fluids may be
brines containing selected solids of appropriate particle size
ranges (for instance, salt crystals or calcium carbonate) and
polymers. Usually, only additives needed for filtration control and
cuttings carrying are present in drill-in fluids.
[0005] Completion fluids are utilized during operations that take
place in the so-called completion phase of wellbore construction,
which is after drilling the wellbore and before commencement of
production of fluids into the wellbore (or before injection of
fluids from the wellbore into a rock formation). A completion fluid
is placed in the well to facilitate final operations prior to
initiation of production, such as setting screens production
liners, packers, downhole valves or shooting perforations into the
producing zone. The fluid is meant to control a well should
downhole hardware fail, without damaging the producing formation or
completion components. Completion fluids are typically brines
(chlorides, bromides and formates), but in theory could be any
fluid of proper density and flow characteristics. The fluids should
be chemically compatible with the reservoir formation fluids, and
are typically filtered to avoid introducing solids to the
near-wellbore area.
[0006] During drilling operation, the workover is referred to the
repair of an existing production well for the purpose of restoring,
prolonging or enhancing the production of hydrocarbons. A workover
fluid, typically a brine, is used during workover operations. Since
the wellbore is in contact with the reservoir during most workover
operation, workover fluids should be clean and chemically
compatible with the reservoir fluids and formation matrix.
[0007] US Publication No. 20060234875 assigned to Halliburton
Energy Services Inc. discloses a wellbore treatment kit that
includes a polymeric solution for placement in a wellbore that
penetrates a subterranean formation and an activator for causing a
polymer to precipitate out of the polymeric solution when it
contacts the polymeric solution, wherein the resulting precipitate
is capable of at least partially blocking a flow of a wellbore
servicing fluid into the subterranean formation. The wellbore
servicing fluid may be, for example, a drilling fluid, a cement
composition, a workover fluid, or combinations thereof. The
polymeric solution may comprise, for example, a poly vinyl
pyrrolidone aqueous solution, and the activator may comprise, for
example, formate brine. When desirable, the precipitate may be
easily and quickly removed from the subterranean formation by
dissolving it in fresh water.
[0008] WO20060234875 assigned to Halliburton Energy Services Inc.
discloses a crosslinkable polymer composition that comprises an
aqueous fluid; a water-soluble polymer comprising carbonyl groups;
an organic crosslinking agent capable of crosslinking the
water-soluble polymer comprising carbonyl groups; and a
water-soluble carbonate retarder. Also provided are methods
comprising: providing the crosslinkable polymer composition;
introducing the crosslinkable polymer composition into a portion of
the subterranean formation; and allowing the crosslinkable polymer
composition to form a crosslinked gel in the portion of the
subterranean formation.
[0009] U.S. Pat. No. 7,322,414B2 assigned to Halliburton Energy
Services Inc. discloses crosslinkable-polymer compositions that may
be useful for, among other things, reducing, stopping, or diverting
the flow of fluids in subterranean formations. The
crosslinkable-polymer compositions may comprise an aqueous fluid, a
chitosan-reacting polymer, chitosan, and a gelation-retarding
additive comprising an acid derivative. Various methods of use are
also provided.
[0010] U.S. Pat. No. 7,833,945B2 assigned to Halliburton Energy
Services Inc. discloses additives and treatment fluids with
improved shale inhibition, and associated methods of use in
subterranean operations. The additives and treatment fluids used
generally comprise a shale-inhibiting component and one or more
silicates. Further, the patent claims a subterranean treatment
fluid comprising: an aqueous base fluid; a shale-inhibiting
component that comprises a nanoparticle source comprising a
heterocyclic compound comprising nitrogen, wherein at least a
portion of the nanoparticle source comprises nanoparticles having
an average particle size of less than about 400 nanometers; and one
or more silicates selected from the group consisting of sodium
silicate and potassium silicate.
[0011] U.S. Pat. No. 7,549,474B2 assigned to Halliburton Energy
Services Inc. claims a method of servicing a wellbore in contact
with a subterranean formation comprising: placing an aqueous
composition comprising a mud displacement fluid and a clay
inhibitor into the wellbore wherein the clay inhibitor is a
nonionic polyacrylamide, a low molecular weight nonionic
polyacrylamide, a high molecular weight nonionic polyacrylamide a
polymeric heterocyclic nitrogen-containing compound, polyvinyl
pyrrolidone or combinations thereof.
[0012] In view of the foregoing, it is an object of the present
application to provide a high performance synthetic thickening
polymer which is (i) capable of providing required thickening or
rheological properties at high temperatures i.e. above 300.degree.
F. and high pressures; and (ii) compatible for brine and water
based oil-well servicing operations such as drill-in, completion,
and workover under HTHP conditions.
[0013] Surprisingly, we have found that a strongly swellable,
moderately crosslinked polyvinyl pyrrolidone (PVP) polymer is able
to provide the required high performance thickening properties
which is suitable for HTHP water and brine based oil-well servicing
fluids. Such polymer may be used alone or in combination with other
at least one HTHP or non-HTHP based Rheology Modifiers (RMs), Fluid
Loss Additives (FLAs) and/or dispersants that are known in the
arts.
SUMMARY OF THE INVENTION
[0014] The present application discloses a water based
High-Temperature High-Pressure (HTHP) fluid composition having a
density of about 8.3 to about 21.0 ppg, comprising: (i) a brine
based fluid; (ii) about 0.5 ppb to about 20 ppb of crosslinked
polyvinylpyrrolidone (PVP); (iii) about 5 ppb to about 100 ppb of
bridging agents selected from the group consisting of CaCO.sub.3
and sized salts; and (iv) optionally about 0 ppb to about 25 ppb of
Fluids Loss Additives (FLA), wherein the HTHP fluid composition is
employed as a drill-in fluid composition, a completion fluid
composition or a workover fluid composition.
[0015] Another aspect of the present application is to employ HTHP
fluid composition in drilling/completion/workover fluid
compositions comprising crosslinked PVP which is capable of
providing required stability in High-Temperature-High-Pressure
(HTHP) based oil-well servicing field operations having a
temperature of 250.degree. F. or above.
[0016] An important aspect of the present application provides a
HTHP fluid composition comprising crosslinked polyvinylpyrrolidone
(PVP) as a thickener or thickening agent in the form of fine white
powder for water based oil-well servicing fluids. The crosslinked
PVP, thickener is prepared by precipitation polymerization of
vinylpyrrolidone (VP) in an organic solvent in the presence of a
crosslinking agent and a free radical polymerization initiator,
wherein the crosslinking agent is present in an amount of from
about 0.1 wt. % to about 5.0 wt. % based on the weight of the
vinylpyrrolidone.
[0017] One another aspect of the present application provides (i) a
method for drilling into a producing zone with limited formation
damage in a subterranean formation; and (ii) a method for
conducting a completion operation in a subterranean formation.
DETAILED DESCRIPTION OF THE INVENTION
[0018] While this specification concludes with claims particularly
pointing out and distinctly claiming that, which is regarded as the
invention it is anticipated that the invention can be more readily
understood through reading the following detailed description of
the invention and study of the included examples.
[0019] By the term "comprising" herein is meant that various
optional, compatible components can be used in the compositions
herein, provided that the important ingredients are present in the
suitable form and concentrations. The term "comprising" thus
encompasses and includes the more restrictive terms "consisting of"
and "consisting essentially of" which can be used to characterize
the essential ingredients such as water, brine, thickener, rheology
modifier (RM), HTHP or non-HTHP based Fluid Loss Additive (FLA),
bridging agent of the present application.
[0020] All references to singular characteristics or limitations of
the present invention shall include the corresponding plural
characteristic or limitation, and vice-versa, unless otherwise
specified or dearly implied to the contrary by the context in which
the reference is made.
[0021] Numerical ranges as used herein are intended to include
every number and subset of numbers contained within that range,
whether specifically disclosed or not. Further, these numerical
ranges should be construed as providing support for a claim
directed to any number or subset of numbers in that range.
[0022] As used herein, the words "preferred," "preferably" and
variants refer to embodiments of the invention that afford certain
benefits, under certain circumstances. However, other embodiments
may also be preferred, under the same or other circumstances.
Furthermore, the recitation of one or more preferred embodiments
does not imply that other embodiments are not useful, and is not
intended to exclude other embodiments from the scope of the
invention.
[0023] References herein to "one embodiment," "one aspect", "one
version" or "one objective" of the invention include one or more
such embodiment, aspect, version or objective, unless the context
clearly dictates otherwise.
[0024] All publications, articles, papers, patents, patent
publications, and other references cited herein are hereby
incorporated herein in their entireties for all purposes to the
extent consistent with the disclosure herein.
[0025] The unit "pounds per barrel" can also be specified as "ppb"
or "lbm/bbl", and wherein one lbm/bbl or ppb is the equivalent of
one pound of additive in 42 US gallons of mud. The "m" is used to
denote mass to avoid possible confusion with pounds force (denoted
by "lbf"). In SI units, the conversion factor is one pound per
barrel equals 2.85 kilograms per cubic meter. For example, 10
lbm/bbl=28.5 kg/m.sup.3.
[0026] The term "crosslinked" herein refers to a composition
containing intra-molecular and/or intermolecular crosslinks,
whether arising through a covalent or non-covalent bonding.
"Non-covalent" bonding includes both hydrogen bonding and
electrostatic (ionic) bonding.
[0027] The term "monomer" refers to the repeat units that comprise
a polymer. A monomer is a compound that chemically bonds to other
molecules, including other monomers, to form a polymer.
[0028] The term "polymer" refers to both linear and branched
polymers derived from one or more monomer units, which may or may
not be crosslinked, or grafted. Non-limiting examples of polymers
include copolymers, terpolymers, tetramers, and the like, wherein
the polymer is random, block, or alternating polymer.
[0029] What is described herein is a water based High-Temperature
High-Pressure (HTHP) fluid composition having a density of about
8.3 to about 21.0 ppg, comprising: (i) a brine based fluid; (ii)
about 0.5 ppb to about 20 ppb of crosslinked polyvinylpyrrolidone
(PVP); (iii) about 5 ppb to about 100 ppb of bridging agents
selected from the group consisting of CaCO.sub.3 and sized salts;
and (iv) optionally about 0 ppb to about 25 ppb of Fluids Loss
Additives (FLA), wherein the crosslinked PVP is prepared by
precipitation polymerization of vinylpyrrolidone (VP) in an organic
solvent in the presence of a crosslinking agent and a free radical
polymerization initiator, wherein the crosslinking agent is present
in an amount of from about 0.1 wt. % to about 5.0 wt. % based on
the weight of the vinylpyrrolidone. Also discloses a method of
drilling and completing operations in a subterranean formation.
[0030] According to the present application, it is directed to
provide a thermally-stable polymer, i.e. crosslinked PVP suitable
for HTHP based conditions. HTHP refers generally to wells that are
hotter and/or at higher pressures than most wells. In accordance
with some aspects, HTHP may refer to a well having an undisturbed
bottom-hole temperature of greater than 300.degree. F. (149.degree.
C.) and a bottom-hole pressure of at least 5000 psi (.about.34.5
Mpa).
[0031] According to one embodiment of the present application, it
is provided with strongly swellable, moderately crosslinked PVP
polymers obtained directly as fine powders by precipitation
polymerization of vinyl pyrrolidone in the presence of
predetermined amount of a multifunctional crosslinking agent and a
free radical initiator in an organic solvent, and wherein the
crosslinked PVP has a Brookfield viscosity at least about 500 to
about 50,000 cps in 4% aqueous solution. The preferred viscosity
ranges of the crosslinked PVP in the present application can be
varied from about 500 to about 50,000 cps or from about 800 to
about 20,000 cps or from about 1000 to about 10,000 cps. The
Brookfield viscosity can be measured at 2.5, 5, 10, 12, 20, 30, or
50 RPM and at 25.degree. C.
[0032] The crosslinked PVP polymer, a thickener of the present
application can be prepared according to granted U.S. Pat. No.
5,073,614, and U.S. Pat. No. 5,130,388 assigned to ISP Investments
Inc. The teachings of these references are advantageously explored
and employed for the purposes of the present application. Further,
the references are incorporated herein in their entirety.
[0033] It is contemplated to employ any other possible
polymerization methods known in the art, which can provide strongly
swellable, moderately crosslinked PVP as fine white powder. Such
polymerization methods can include, but are not limited to,
precipitation polymerization, inverse emulsion polymerization, gel
polymerization, dispersion polymerization, solution polymerization,
emulsion polymerization, bulk polymerization, suspension
polymerization, Liquid dispersion polymerization (LDP) and ionic
polymerization.
[0034] Other preferred polymerization techniques employed to
prepare the polymer of the present application are duly disclosed
in (1) "Principles of Polymerization" .sup.4th edition, 2004, Wiley
by George Odian and (2) WO2012061147A1 assigned to ISP Investments
Inc., which are incorporated herein by reference in their entirety.
Further, the polymerization of the present application may
optionally require suitable catalysts or initiators, stabilizers,
salts, pH adjusting agents, co-dispersants, thickeners, solvents,
acidic agents, basic agents, and/or photoinitiators depending on
type of polymerization technique being employed, and one skilled in
the art can easily derive such information from the relevant
literature known in the art or from "Principles of Polymerization"
.sup.4th edition, 2004, Wiley by George Odian, which is
incorporated herein by reference in its entirety.
[0035] The polymerization temperature for preparing crosslinked PVP
can be ranged from 40.degree. to 150.degree. C., and other
preferred temperature ranges are 55.degree. to 100.degree. C.; or
60.degree. to 80.degree. C.
[0036] In accordance with the present application, strongly
swellable, moderately crosslinked PVP polymers can be prepared
directly in the form of fine, white powders by precipitation
polymerization of vinylpyrrolidone in the presence of a
predetermined amount of a crosslinking agent and a free radical
polymerization initiator in an organic solvent, preferably an
aliphatic hydrocarbon, e.g. a C.sub.3-C.sub.10 saturated, branched
or unbranched, cyclic or acyclic aliphatic hydrocarbon, and most
preferably cyclohexane or heptane, or mixtures thereof.
[0037] The amount of solvent used for preparing the crosslinked PVP
of the present application should be sufficient to dissolve the
reactants and to maintain the polymer precipitate in a stirrable
state at the end of the polymerization. Generally, the amount of
the solvent can be ranged from about 10 to 50 wt % solids,
preferably 15-40 wt % solids, or 17-30 wt % solids, or 17-25 wt %
solids.
[0038] Suitable crosslinking agents for preparing the crosslinked
PVP comprise at least two olefinic double bonds. Examples of the
crosslinking agents are selected from the group consisting of
N,N'-divinylimidazolidone (DVI), N,N',N''-triallyl-triazine-trione,
methyene-bis-acryamide, methylene-bis-(meth)acrylamide, triallyl
amine, triallylglucose, ethyleneglycol-di-(meth)acrylate,
diethyleneglycol-di-(meth)acrylate,
triethyleneglycol-di-(meth)acrylate,
tetraethyleneglycol-di-(meth)acrylate,
polyethyleneglycol-di-(meth)acrylate,
pentaerythritol-tri-allylether, pentaerythritol-di-allylether,
pentaerythritol-tetra-allylether,
pentaerythritol-di-(meth)acrylate, pentaerythritol
tri(meth)acrylate, pentaerythritol-tetra-(meth)acrylate,
1-vinyl-3-(E)-ethylidene-pyrrolidone (EVP), allyl methacrylamide,
allyl glycidyl ether, glycidyl acrylate, hydroxyacrylamide,
triallyl-1,3,5-triazine-2,4,6(1H,3H, 5H)-trione,
2,4,6-triallyloxy-1,3,5-triazine and/or divinylbenzene. Preferred
crosslinking agent for preparing the crosslinked PVP of the present
application is selected from the group consisting of
N,N'-N,N'-divinylimidazolidone (DVI),
pentaerythritol-tri-allylether,
triallyl-1,3,5-triazine-2,4,6(1H,3H,5H)-trione and
2,4,6-triallyloxy-1,3,5-triazine. The amount of crosslinking agent
can be changed from about 0.1 to about 5% by weight of vinyl
pyrrolidone. In one non-limiting embodiment, the crosslinking agent
is present in an amount of from about 0.3 wt. % to about 1.0 wt. %
based on the weight of the vinylpyrrolidone. In another
non-limiting embodiment, the crosslinking agent is present in an
amount of from about 0.4 wt. % to about 0.8 wt. % based on the
weight of the vinylpyrrolidone.
[0039] According to one embodiment of the present application, the
precipitation polymerization can be carried out in the presence of
a suitable free radical polymerization initiator. Such free radical
initiators can include, but are not limited to, various derivatives
of peroxides, peresters and/or azo compounds. Examples of the free
radical initiators can include, but are not limited to, dicumyl
peroxide, dibenzoyl peroxide, 2-butanone peroxide, tert-butyl
perbenzoate, di-tert-butyl peroxide,
2,5-bis(tert-butylperoxy)-2,5-dimethylhexane, bis(tert-butyl
peroxyisopropyl)benzene, and tert-butyl hydroperoxide), diacyl
peroxides, cumene hydroperoxide, dialkyl peroxides, hydroperoxides,
ketone peroxides, monoperoxycarbonates, peroxydicarbonates,
peroxyesters, and peroxyketals, including tertiary butyl
perbenzoate, tertiary butyl peroctoate in diallyl phthalate,
diacetyl peroxide in dimethyl phthalate, dibenzoyl peroxide,
1-hydroxy cyclohexyl-1-phenyl ketone, bis (2,4,6-trimethyl
benzoyl)phenyl phosphine, benzoin ethyl ether,
2,2-dimethoxy-2-phenyl acetophenone, di(p-chlorobenzoyl)peroxide in
dibutyl phthalate, di(2,4-dichlorobenzoyl)peroxide with dibutyl
phthalate, dilauroyl peroxide, methyl ethyl ketone peroxide,
cyclohexanone peroxide in dibutyl phthalate,
3,5-dihydroxy-3,4-dimethyl-1,2-dioxacyclopentane,
t-butylperoxy(2-ethyl hexanoate), caprylyl peroxide,
2,5-dimethyl-2,5-di(benzoyl peroxy)hexane, 1-hydroxy cyclohexyl
hydroperoxide-1, t-butyl peroxy(2-ethyl butyrate),
2,5-dimethyl-2,5-bis(t-butyl peroxy)hexane, cumyl hydroperoxide,
diacetyl peroxide, t-butyl hydroperoxide, ditertiary butyl
peroxide, 3,5-dihydroxy-3,5-dimethyl-1,2-oxacyclopentane, and
1,1-bis(t-butyl peroxy)-3,3,5-trimethyl cyclohexane and
di-(4-t-butyl cyclohexyl)peroxydicarbonate, azo compounds such as
azobisisobutyronitrile and azobiscyclohexanenitrile (e.g.,
2,2'-azobis(2-methyl-propanenitrile),
2,2'-azobis(2-methylbutanenitrile), and
1,1'-azobis(cyclohexanecarbonitrile)) and the like mixtures.
[0040] The preferred initiators can include acyl peroxides such as
diacetyl peroxide, dibenzoyl peroxide and dilauryl peroxide;
peresters such as t-butylperoxy pivalate, tert-butyl
peroxy-2-ethylhexanoate; peroxides such as di-tert-butyl peroxide;
percarbonates such as dicyclohexyl peroxydicarbonate; and azo
compounds such as 2,2'-azobis-(isobutyronitrile),
2,2'-azobis-(2,4-dimethylvaleronitrile),
1,1'-azobis-(cyanocyclohexane), and
2,2'-azobis-(methylbutyronitrile).
[0041] A particularly preferred embodiment of the present
application discloses a stable water based
High-Temperature-High-Pressure (HTHP) drill-in fluids composition
having a density of 8.3 to about 21.0 ppg, comprising: (i) brine
based fluids; (ii) about 0.5 ppb to about 20 ppb of crosslinked PVP
as thickeners; (iii) about 5 ppb to about 100 ppb of bridging
agents are CaCO.sub.3 or sized salts; and (iv) optionally about 0
ppb to about 25 ppb of HTHP or non-HTHP based Fluid Loss Additives
(FLA).
[0042] Bridging agent used in the present application can be
CaCO.sub.3 and/or sized salts. Commercially available CaCO.sub.3
used in the present application can include, but are not limited
to, Baracarb.RTM. 5, 25, 50, 150, 400, 600 and 1200, which is
available from Halliburton Company.
[0043] Sized salts of the present application can include, but are
not limited to, sodium chloride, potassium chloride, calcium
chloride, sodium formate, potassium formate, sodium bromide,
potassium bromide, calcium bromide, sodium acetate, potassium
acetate, and the like. The preferred sized salt is sodium chloride.
Further, the sized salts have a particle size in a range of
approximately 1 micron to approximately 10,000 microns. For a sized
salt fine grade, a particle size can be in a range of approximately
1 micron to approximately 800 microns. For a sized salt medium
grade, a particle size can be in a range of approximately 100
micron to approximately 1,500 microns. For a sized salt coarse
grade, a particle size can be in a range of approximately 1,000
micron to approximately 10,000 microns.
[0044] Another embodiment of the present application provides a
stable water based High-Temperature High-Pressure (HTHP) completion
and workover fluid compositions having a density of 8.3 to 21.0
ppg, comprising: (i) brine based fluids; (ii) about 0.5 ppb to
about 20 ppb of crosslinked PVP as thickener; and (iii) optionally
about 5 ppb to 100 ppb bridging agent.
[0045] The aqueous drill-in/completion/workover fluid composition
of the present application can employ either (i) fresh water or
(ii) a suitable brine solution as a base fluid during drilling
operations. The fluid composition of the present application may
also comprise seawater or a solution of a salt or a solution of a
combination of salts required thereof.
[0046] Generally, the brine based fluid of the present application
is present in a sufficient amount to achieve the density of from
about 8.3 to 21.0 ppg. The brine based fluid may be an aqueous
solution of one or more density-increasing water-soluble salt. The
density increasing water-soluble salt may be selected from the
group consisting of alkali metal halides (for example, sodium
chloride, sodium bromide, potassium chloride, potassium bromide,
magnesium chloride, ammonium chloride) alkali metal carboxylates
(for example, sodium formate, potassium formate, caesium formate,
sodium acetate, potassium acetate or caesium acetate), sodium
carbonate, potassium carbonate, alkaline earth metal halides (for
example, calcium chloride and calcium bromide), and zinc halide
salts (zinc chloride, zinc bromide) and mixtures thereof. The salt
for preparing the brine based fluid of the present application is
selected from the group consisting of sodium chloride, potassium
chloride, calcium chloride, magnesium chloride, ammonium chloride,
zinc chloride, sodium bromide, calcium bromide, zinc bromide,
potassium formate, cesium formate, sodium formate and mixtures
thereof.
[0047] One preferred embodiment of the present application
discloses a stable water based High-Temperature-High-Pressure
(HTHP) drill-in/completion/workover fluid composition comprising a
Fluid Loss Additive (FLA) which is stable and compatible for HTHP
and non-HTHP based oil-well servicing applications. Suitable Fluid
Loss Additives of the present application can include, but are not
limited to, Polydrill, Alcomer.RTM. 242 and Alcomer.RTM. 507
(available from BASF); KEM-SEAL (available from Baker Hughes);
DURALON (available from MI-Swaco); DRISCAL.RTM. D (available from
Drilling Specialties Company); Hostadrill.RTM. (available from
Clariant Oil Servies); Therma-chek.RTM. (available from Halliburton
Company); terpolymer of acrylamide (AM)/2-acrylamido-2-methyl
propanesulfonic acid (AMPS)/cationic monomers; carboxymethyl
cellulose; carboxy methyl hydroxy ethyl cellulose; lignite; xanthan
gum; starch; hydroxy ethyl methyl cellulose; hydroxy propyl methyl
cellulose; hydroxy ethyl cellulose; guar gum; hydroxy propyl guar;
carboxy methyl hydroxy propyl guar; hydroxy ethyl guar; and
mixtures thereof.
[0048] The Fluid Loss Additive (FLA) described herein typically has
a weight average molecular weight (MW) over 3,000 daltons,
particularly over 10,000 daltons, and more particularly over
100,000 daltons. In one non-limiting embodiment, the weight average
molecular weight is in a range of from 5,000 to 5,000,000 daltons.
In another non-limiting embodiment, the weight average molecular
weight is in a range of from 10,000 to 500,000 daltons. In yet
another non-limiting embodiment, the weight average molecular
weight is in a range of from 50,000 to 400,000 daltons. The weight
average molecular weight can be determined by GPC techniques that
are know in the art. The required amount of FLA for the desired
composition of the present application is in a range of from about
0 ppb to about 30 ppb; or about 5 ppb to about 20 ppb; or about 8
ppb to about 15 ppb.
[0049] According to an additional embodiment of the present
application, it is contemplated to employ optionally at least one
rheology modifying agents that are known in the art. The suitable
rheology modifiers can include, but not limited to, crosslinked,
linear poly(vinyl amide/polymerizable carboxylic acid) copolymer;
poly(vinylpyrrolidone/acrylic acid); poly[vinyl pyrrolidone
(VP)/acrylic acid(AA)] copolymer; terpolymer of acrylamide
(AM)/2-acrylamido-2-methyl propanesulfonic acid (AMPS)/hydrophobe;
terpolymer of acrylamide (AM)/2-acrylamido-2-methyl propanesulfonic
acid (AMPS)/C.sub.12-25 alkyl acrylate; carboxymethyl cellulose;
hydroxyethylcellulose; carboxymethylhydroxyethyl cellulose;
sulphoethylcellulose; starch derivatives/crosslinked starch
derivatives including carboxymethyl starch, hydroxyethylstarch,
hydroxypropyl starch; bacterial gums including xanthan, welan,
diutan, succinoglycan, scleroglucan, dextran, pullulan; plant
derived gums such as guar gum, locust-bean gum, tara gum and their
derivatives; polyanionic cellulose (PAC); hydroxyethyl cellulose
(HEC); hydroxypropyl cellulose (HPC); carboxymethyl hydroxyethyl
cellulose (CMHEC); carboxymethyl cellulose (CMC); xanthan gum; guar
gum; and mixtures thereof.
[0050] The water based fluids compositions of the present
application is suitable for high-temperature high-pressure (HTHP)
drill-in/completion/workover operations having a temperature
greater than (>) 250.degree. F., wherein, the non-HTHP drilling
operations having a temperature of ambient to about 250.degree.
F.
[0051] Suitable pH for these stable water based compositions of the
present application is in a range of from about 6.0 to about
13.0.
[0052] The water based drill-in/completion/workover fluid
compositions of the present application may comprise additional
additives for improving the performance of oil-well servicing
operations with respect to one or more properties. Examples of such
additional additives may be selected from the group including but
not limited to bactericides, detergents and emulsifiers, solid and
liquid lubricants, gas-hydrate inhibitors, corrosion inhibitors,
defoaming agents, scale inhibitors, enzymes, oxidizing
polymer-breakers, emulsified hydrophobic liquids such as oils, acid
gas-scavengers (such as hydrogen sulfide scavengers), thinners
(such as lignosulfonates), demulsifying agents and surfactants
designed to assist the clean-up of invaded fluid from producing
formations, polymeric additives, dispersants, shale stabilizers or
inhibitors, pH controlling agents, wetting agents, biopolymers, pH
controlling agents or mixture thereof. Preferred additives can
include polymeric additives, filtration control additives,
dispersants, shale stabilizers or inhibitors, clay swell
inhibitors, pH controlling agents or buffers, emulsifiers,
antifoaming agents, wetting agents, surfactants, corrosion
inhibitors, lubricants, biocides or mixture thereof.
[0053] Further, it is contemplated that crosslinked
polyvinylpyrrolidone of the present application can advantageously
be employed in various other possible oil and gas field
applications including but not limited to rheology
modifier/thickener/suspension agent for drilling/drill-in/packer
fluids, cementing viscosifier, friction reducer in
brine/salt/saline based drilling operations, friction reducer in
oil-well fracturing, shale swell inhibitor/clay stabilizer, fluid
loss additive, viscosifier in seawater/saline/brine based drilling
fluids, filtration control, viscosifier for oil-well stimulation,
drilling-aids for oil/water/geological drillings, completion fluids
and workover fluids, invert-drilling fluids, and/or polymer
flooding for enhanced oil recovery.
[0054] According to a preferred embodiment of the present
application, it provides a method for drilling into a producing
zone with limited formation damage in a subterranean formation,
comprising the steps of: (a) drilling a borehole into a formation
adjacent to the producing zone; (b) circulating the water based
HTHP fluid composition of any one of claims 1-12 in the bore hole;
and (c) drilling into the producing zone while continuing step
(b).
[0055] Another embodiment of the present application discloses a
method for conducting a completion operation in a subterranean
formation, comprising using the water based HTHP fluid composition
in the completion operation, wherein the completion operation is
cementing a borehole, wherein the completion operation comprises
isolating or consolidating a narrow gradient zone in the
formation.
[0056] Further, the present invention is illustrated in detail by
way of the below given examples. The examples are given herein for
illustration of the invention and are not intended to be limiting
thereof.
EXAMPLE 1
[0057] Drill-in/completion/workover fluids as described in Table 1
were made on a 350 ml scale containing (i) crosslinked PVP polymer
(FlexiThix.TM., available from Ashland Inc.) (ii) 20% brine
solution comprising NaBr, CaCl.sub.2 or CaBr.sub.2; and (iii) 50%
NaOH as a pH adjusting agent. Sufficient mixing was required to
facilitate dissolving of the polymer and avoid local viscosified
agglomerates (fish eyes). The completion and workover fluids were
allowed to agitate for 5 to 15 minutes between the addition of each
component and with 30 to 50 minutes total for complete and
homogenous mixing. Rheological (thickening) properties were then
measured on a Fann 35 before and after hot rolling (BHR and AHR)
aging tests.
[0058] The drill-in/completion/workover fluids prepared were hot
rolled under N.sub.2 pressure of 350 psi at 400.degree. F. for 16
hours aging. BHR and AHR rheology or thickening results are
provided in Table 1.
TABLE-US-00001 TABLE 1 Thermal Stability of Crosslinked PVP in
Various Brines for Completion and Workover Fluids Compositions
Composition Mixing time 12503-128-1 12503-128-3 12503-128-4 20%
NaBr, ml -- 340 -- -- 20% CaCl.sub.2, ml -- -- 340 -- 20%
CaBr.sub.2, ml -- -- -- 340 NaOH, 50%, 30 sec 2 drops 2 drops
2drops crosslinked 20 min 10 9.5 9 PVP, ppb Aging condition
400.degree. F./16 hr hot rolling Density, ppg ~10.1 ~10.3 ~10.3
Ret* Ret* Ret* Fann data @ 120.degree. F. BHR AHR (%) BHR AHR (%)
BHR AHR (%) 600 rpm 84 90 107 78 77 99 70 49 70 300 rpm 61 61 100
56 54 96 50 32 64 200 rpm 51 46 90 45 44 98 41 25 61 100 rpm 31 32
103 32 32 100 29 17 59 6 rpm 12 9 75 9.5 11 116 9.5 5 53 3 rpm 10
8.5 85 8 10 125 8.5 4 47 10 s gel, lb/100 ft.sup.2 8.5 8.5 100 6
9.5 158 7 3.5 50 PV, cps 23 29 126 22 23 105 20 17 85 YP, lb/100
ft.sup.2 38 32 84 34 31 91 30 15 50 pH value 10.1 7.6 -- 9.7 9.1 --
9.3 7.0 -- Ret*: Retention rate (%); AHR: After Hot Rolling 16 hrs
at 400.degree. F.; 20% NaBr was made by dissolving 160 g NaBr in
640 g of water; 20% CaCl.sub.2 was made by dissolving 160 g
CaCl.sub.2 in 640 g of water; 20% CaBr.sub.2 was made by dissolving
160 g CaBr.sub.2 in 640 g of water.
[0059] Table 1 demonstrates that crosslinked PVP is very thermally
stable in the presence of 20% NaBr and CaCl.sub.2. After aging, the
rheologies are greatly retained with high 3/6 rpm viscosities,
showing a good suspension capability. Crosslinked PVP in 20%
CaBr.sub.2 also maintains thermal stability to a certain extent.
The (i) thermal stability and (ii) good rheology retention makes
crosslinked PVP suitable for HTHP completion and workover
fluids.
EXAMPLE 2
[0060] Drill-in/completion/workover fluids as described in Table 2
were made on a 350 ml scale containing (i) about 9 to 10 ppb
crosslinked PVP polymer (FlexiThix.TM., available from Ashland
Inc.); (ii) 20% brine solution of NaBr, CaCl.sub.2 or CaBr.sub.2;
and (iii) CaCO.sub.3. 50% NaOH was used as a pH adjusting agent.
Sufficient mixing was required to facilitate dissolving of the
polymer and avoid local viscosified agglomerates (fish eyes). The
completion and workover fluids were allowed to agitate for 5 to 15
minutes between the addition of each component and with 30 to 50
minutes total for complete and homogenous mixing. Rheological
(thickening) properties were then measured on a Fann 35 before and
after hot rolling (BHR and AHR) aging tests.
[0061] The drill-in/completion/workover fluids prepared were hot
rolled under N.sub.2 pressure of 350 psi at 400.degree. F. for 16
hours aging. BHR and AHR rheology or thickening results are
provided in Table 2.
TABLE-US-00002 TABLE 2 Thermal Stability of Crosslinked PVP in
Various Brines/CaCO.sub.3 from Drill-in, Completion and Workover
Fluids Compositions Composition Mixing time 12503-132-1 12503-137-3
12503-132-2 12503-137-2 20% NaBr, ml -- 340 -- -- -- 20%
CaCl.sub.2, ml -- -- 340 -- -- 20% CaBr.sub.2, ml -- -- -- 340 --
40% CaBr.sub.2, ml -- -- -- -- 340 NaOH, 50%, 30 sec 2 drops 2
drops 2 drops 2 drops Crosslinked 20 min 10.0 9.5 9.0 9.0 PVP, ppb
CaCO.sub.3, 10 min 40 40 40 40 25 micron, ppb Aging condition
400.degree. F./16 hr hot rolling Density, ppg ~11 ~11 ~11 ~12.1
Ret* Ret* Ret* Ret* Fann data @ 120.degree. F. BHR AHR (%) BHR AHR
(%) BHR AHR (%) BHR AHR (%) 600 rpm 94 56 60 95 69 73 77 69 90 88
76 86 300 rpm 72 39 54 71 48 68 54 47 87 61 52 85 200 rpm 60 32 53
59 39 66 44 36 82 49 41 84 100 rpm 44 22 50 42 27 64 31 23.5 76 33
28 85 6 rpm 16 6 38 15 7 47 10 6 60 9 6 67 3 rpm 14 5 36 14 6 43 9
5 56 8 5 63 10 s gel, lb/100 ft.sup.2 12 5 42 11 5 45 8 6 75 7 4.5
64 PV, cps 22 17 77 24 21 88 23 22 96 27 24 89 YP, lb/100 ft.sup.2
50 22 44 47 27 57 31 25 81 34 28 82 pH value 9.5 6.8 -- 9.7 6.4 --
9.0 6.1 -- 9.0 7.9 -- *Retention rate (%); AHR: After Hot Rolling
16 hrs at 400.degree. F.; 20% NaBr was made by dissolving 160 g
NaBr in 640 g of water; 20% CaCl.sub.2 was made by dissolving 160 g
CaCl.sub.2 in 640 g of water; 20% CaBr.sub.2 was made by dissolving
160 g CaBr.sub.2 in 640 g of water; 40% CaBr.sub.2 was made by
dissolving 320 g CaBr.sub.2 in 480 g of water.
[0062] Table 2 shows that the crosslinked PVP is significantly
thermally stable in the brine solution of NaBr, CaCl.sub.2, and
CaBr.sub.2 containing CaCO.sub.3. After aging, the rheologies are
greatly retained with high 3/6 rpm viscosities, showing good
suspension capabilities. The thermal stability and good rheology
retention makes crosslinked PVP suitable for HTHP drill-in,
completion and workover fluids composition and their related
applications.
[0063] While this invention has been described in detail with
reference to certain preferred embodiments, it should be
appreciated that the present invention is not limited to those
precise embodiments. Rather, in view of the present disclosure,
which describes the current best mode for practicing the invention,
many modifications and variations can present themselves to those
skilled in the art without departing from the scope and spirit of
this invention.
* * * * *